Malcolm mcdowell



(No Model.)

1 M. MCDOWELL.

DEVICE FOR FASTENING THE TEETH OP HARROWS AND HAY RAKES. No. 286,213. Patented Oct. 9, 1883.

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MALCOLM MODOTVELL, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONEHALF TO IRVIN MCDOTVELL, OF SAN FRANCISCO, CALIFORNIA.

DEVICE FOR FASTENING THE TEETH F HARROWS AND HAY-RAKES.

SPECIFICATION forming part of Letters Patent No. 286,213, dated October 9, 188

Application filed February 10, 1883.

To all whom it may concern.-

Be it known that I, lliIALOOLM MCDOWELL, a citizen of the United States, residing in the city of Chicago, county of Cook, and State of 5 Illinois, have invented a new and useful Device for Fastening and Firmly Holding in their Place the Teeth of Harrows and Hay-Rakes, of which the following is a specification.

The object of my invention is to place and I0 securely fasten the teeth of harrows and hayrakes.

The nature of my invention is a compound metal tube composed of two members, which, in either the harrow or hay-rake, form the transverse bar for holding the teeth. These membersin their erosssections are segments of arcs. That of the principal member is a segment greater than a semicircle. That of the lesser is less than a semicircle. The lesser member, which is the-upper one in the harrow and the front one inthe hay-rake, is flattened along the upper side, and is so rabbeted on each edge as to fit on and into the principal member, like a cover fitted to its place by a chine or collar. There are two holes for each tooth in this compound bar, one in each member, each opposite the other. This tubular bar is made of two members,instead of a simple closed pipe or tube, as is done by others, because it thus permits the holes in each to be made by a punch instead of a drill,and because one of these holes,being non-cylindrical, cannot be drilled, and could not be punched in a closed pipeor tube. In this compound 3 5 tubular bar I fasten a teeth of my own invention, made from the blank for that purpose, a patent for which was granted to me August 21, 1883, No. 283,410. The two holes in the compound bar, through which this tooth is passed and in which it is fastened, are made to correspond. in form to the cross-section of the tooth at the places where it is held. The hole in the principal member-the lower one in the harrow and rear one in the hay-rake 4 5 is of lentieular form at both surfaces of the tube. At the outer surface it is larger than at the inner surface, thus making the walls of the opening flare outward to such an extent and in such way as to closely conform to the shape of the teeth at that place. The hole in the lesser mcmbcr-the upper one in the har- (No'modeL) row and the front one in the hay-rak.eis cylindrical.

In the drawings, Figure 1 is a crossseetion, and Fig. 2 a longitudinal section, of the com- 5 5 pound tubular bar, with harrow-teeth in elevation. Fi 3 and 4 are similar views, showing the upper portion of raketeeth.

I have rolled the parts to this compound tubular bar in an ordinary rolling-millthe 6o principal member on a former, and the lesser one in passes of my own designing. I am confidentno other party has ever made such a compound bar, from the fact that all the experts in tube and pipe rolling I11 ve met were of opinion that the principal mem ber could not be successfully formed by any rolling process.

My method of constructing this compound bar and of fastening the teeth therein is, having rolled the two members, to punch the lenticular-shaped hole downward through a die enough larger than the punch to give the desired flare to the opening to closely embrace the tooth; then, having punched the 7? round hole in the lesser member, and placed the two members togetherthe holes in the one opposite those in the otherto insert the teeth through the lenticular flaring shaped hole till they are firmly wedged therein, and at the same time have protruded through the (round hole far enough to allow the upper end to be nutted, thus preventing its being drawn out of the bar, whose two members, by the wedging of the teeth in the lenticular-shaped hole in the larger member, and the nutting of their ends above the lesser one, are thus firmly bound and held together. TV hen so fastened, they are ready for coupling and attaching to form the harrow or hay-rake.

I am aware that heretofore harrows have been formed with tubular and channel-iron tooth-bars and compound tooth-bars of channel-iron; also, that in horse-rakes similar two part castings have been employed to secure the rake-teeth. I am further aware that harrow-teeth have been formed with diamond shaped necks and serew-threaded ends, and with tapering shanks (angular in cross-section)terminating in cylindrical screw-threaded I 00 ends, and adapted to fit corresponding openings in the harrow-irame, the teeth being drawn upward or wedged in place by means of nuts upon their screw-threaded ends. I therefore do not claim any of, these features;

7 2. In combination with the described compound tubular tooth-bar, the tooth formed so 15 as to fit the lenticular and cylindrical openings in the bar, and having the tightening-nut upon its threaded end, substantially as shown and described.

In witness whereof I have, this 26th day of December, 1}. D. 1882, hereto set my hand.

MALCOLM MCDONVELL.

Witnesses:

MALCOLM McDoWnLL Jr. SAML. KIMBERLY. 

